1. Field of the Invention
The present invention relates, in general, to quick connectors and, more specifically, to quick connectors including an internal retainer and means providing an indication of complete coupling between the male and female elements of the quick connector.
2. Description of the Art
Snap-fit or quick connectors are employed in a wide range of applications, particularly, for joining fluid carrying conduits in automotive and industrial application. In a typical quick connector, a retainer is fixedly mounted within a bore in a housing of a female connector component or element. The retainer has a plurality of radially extending legs which extend inwardly toward the axial center line of the bore in the housing. A tube or fitting to be sealingly mounted in the bore in the female component includes a radially upset portion or flange which abuts an inner peripheral surface of the retainer legs. Seal and spacer members as well as a bearing or top head are typically mounted in the bore ahead of the retainer to form a seal between the housing and the male fitting when the male fitting is lockingly engaged with the retainer legs.
While such a retainer is usually effective in releasably coupling the male and female elements of a quick connector, it is possible that the male fitting may be partially, but not fully seated or coupled to the internal seal elements in the bore of the female component and not fully locked in position by the retainer legs. In this partially engaged position, the male fitting may work itself free of the housing thereby leading to leaks in the fluid delivery system.
As it is desirable to ensure that the male and female elements are fully coupled to prevent leaks, various indicators have been provided to indicate a full coupling or seating of the male fitting in the female element. In one type of indicator shown in U.S. Pat. No. 4,925,217, a deformable member is assembled within the fitting which includes elongated members extending out of the housing between the male and female elements prior to coupling and which are retracted, and no longer visible, once the coupling has been fully accomplished. The annular member in this device remains in assembly with the quick connector and contributes to component count, tolerance stack-up and possible misassembly. Furthermore, the elongated members which are visible during non-coupling of the connector are, by design, not visible after coupling is fully effected. In many applications, such as an extremely crowded engine compartment of a motor vehicle, the installed coupling may be difficult to see and inspect closely. Thus, the inability to see the elongated members from a distance or from an awkward position will not result in a high degree of confidence that the coupling has in fact fully taken place.
Other types of visual indicators, as shown in U.S. Pat. No. 4,946,205, are removable after full coupling of the male and female quick connector elements. However, the indicator disclosed in this patent is complex and adds considerable axial length to the quick connector.
To overcome these problems and to provide an advancement in the quick connector art, the quick connect insertion indicator clip disclosed in U.S. Pat. No. 5,152,555, and assigned to the assignee of the present invention, was devised. This indicator clip includes a flag portion positioned externally of the quick connector and has members extending from the flag portion to embrace the female element of the quick connector. Engagement tabs extending from the members through registering apertures in the female element will contact an abutment surface formed on the male element upon fully coupling of the male and female components to enable removal of the indicator device as verification of complete or full coupling. When coupling is incomplete or not fully effected, the indicator device cannot be removed from the female component.
While the insertion indicator clip disclosed in U.S. Pat. No. 5,152,555 provides an easily visible indication of complete coupling of quick connector components, the quick connector still requires a separate retainer to lockingly couple the male and female components together.
U.S. Pat. No. 5,102,313 discloses a retainer clip having a centrally located slot for envelopingly engaging the radial flange on a male conduit when the male conduit is fully inserted into the female portion of a coupler. However, in this arrangement, if the clip is inserted into the housing axially ahead of the radial flange on the male conduit, the length of the male conduit between the flange and the forward tip end of the male conduit is sufficient to at least partially engage a seal mounted in the female housing. This could cause a subsequent leak since the male conduit, while appearing to be fully inserted into the female housing, is only partially engaged with the seal and, further, is not locked in a fixed portion in the female housing by the retainer clip.
To address these problems, a quick connector with a snap-on retainer disclosed in U.S. Pat. No. 5,542,716 was developed. This retainer is releasably insertable into a transverse bore formed in female housing and includes an internal recess engageable with the radial flange on the male component only when the male component is fully coupled in an axial bore in the female component. The engagement between the recess and the radial flange permits full insertion of the retainer into the transverse bore and locks the male component and the female component together. The female component has opposed interior surfaces spaced sufficiently apart to permit the deflectable legs on the retainer to flex apart while they are being slidingly urged over the male component and to snap over the male component in the locked position. The opposed surfaces block full insertion of the retainer into the female component when the male component is not fully seated in the component. Lock projections on the retainer releasably lock the retainer in a partially inserted, shipping position in the transverse bore in the female component. This quick connector meets the required functions of providing a visual indication of a sealed and locked connection between the male and female components, providing an "avalanche effect" retainer clip, is releasible without special tools, and insures that the male component be fully inserted into the female component before the retainer can be urged into the latched position.
While the above-described quick connectors with indicators provide a visual indication of a sealed and locked connection between the male and female components, the indicator clips are typically formed of plastic. A thermal incident, such as fire caused by a vehicle crash or the combustion of fluid leaking from the quick connector or associated fluid conduits, can completely destroy the quick connector and the visual indicator. This leaves no visible evidence that the quick connector was properly locked prior to or after the event leading to the thermal incident. Such information is valuable in terms of determining the long term, crash resistant reliability of the quick connector.
Thus, it would be desirable to provide a quick connector with means which provides a visual indication of the locked connection between the male and female components of the quick connector despite any thermal incident which may damage or destroy the other portions of the quick connector. It would also be desirable to provide a quick connector with an after incident clip in which the clip can be integrated into the quick connector without requiring substantial modifications to the design and construction of the quick connector itself. It would also be desirable to provide a quick connector with an after incident clip in which the after incident clip does not interfere with the low insertion force and high pullout force characteristics of the quick connector.